21
5Connectingtopowersupply
MINITRAC 31 • Foundation Fieldbus
41782-EN-211203
5 Connecting to power supply
5.1 Preparing the connection
Alwayskeepinmindthefollowingsafetyinstructions:
•
The electrical connection must only be carried out by trained,
qualiedpersonnelauthorisedbytheplantoperator.
•
If overvoltage surges are expected, overvoltage arresters should
be installed.
Warning:
Onlyconnectordisconnectinde-energizedstate.
Note:
Installadisconnectingdevicefortheinstrumentwhichiseasyto
access. The disconnecting device must be marked for the instrument
(IEC/EN61010).
The instrument is designed in protection class I. To maintain this
protection class, it is absolutely necessary that the ground conductor
be connected to the internal ground terminal. Take note of the national
installation regulations.
Supply voltage and signal output are carried on separate connection
cables if reliable separation is required. The supply voltage range can
dierdependingontheinstrumentversion.
Thedataforpowersupplyarespeciedinchapter"Technical data".
General requirements
•
Make sure that the cable used has the required temperature resist-
anceandresafetyformax.occurringambienttemperature
•
Usecablewithroundcrosssectionforinstrumentswithhousing
andcablegland.Toensurethesealeectofthecablegland(IP
protectionrating),ndoutwhichcableouterdiameterthecable
gland is suitable for.
•
Useacableglandttingthecablediameter.
•
Unusedcableglandsdonotoersucientprotectionagainst
moisture and must be replaced by blind plugs.
Voltage supply
Forpowersupply,anapproved,three-wireinstallationcablewithPE
conductor is required.
Signal cable
Use for the signal output a cable according to the respective bus
specications.
Metric threads
Inthecaseofinstrumenthousingswithmetricthread,thecable
glandsarescrewedinatthefactory.Theyaresealedwithplastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
Safety instructions
Voltage supply via mains
voltage
Select connection cable
Cable glands